How do I enable the line selection features for the Cisco 8800 phones on Communications Manager Express (CME)?

Many of us who have deployed the Cisco 88XX phones have run across 2 features that are life savers when working with multi-line phones connected to CUCM. Those features are "Show ALL Calls On Primary Line" and "Revert All Calls". For those who haven't used those features before I recommend checking out Amy Engineer's blog on why they are helpful and how they work with CUCM.

https://amyengineer.com/tag/8841/

While these 88XX line selection options have existed in the full Unified Communications Manager offering for a while. These options are not officially available in CME at the time of this writing. Luckily, since the phones have the functionality in firmware, there is a bit of a dirty hack to invoke these features in CME.

The following configuration will enable the "Show ALL Calls On Primary Line" feature on ALL phones.

telephony-service
service phone allCallsOnPrimary 1

The following configuration will enabled the "Revert All Calls" feature on ALL phones.

telephony-service
service phone revertToAllCalls 1

After those features have been enabled the phone profiles (config files) need to be re-created.  The following commands can be used to recreate the profiles.

voice register global
 no create profile
 create profile

Then we can validate the configs or skip this part and just reboot the phones and test.  Here's a sample scenario to check the config file.  Assuming CME is writing the config files to a directory called "its" and there is a phone with a name of "SEP101010101010", the following cli commands would show if the new configuration options are written to the config file.

more bootflash:/its/SEP101010101010.cnf.xml | i allCallsOnPrimary
and
more bootflash:/its/SEP101010101010.cnf.xml | i revertToAllCalls

After validating the the new addition to the configuration the phones will need to be rebooted and then voilà the new features are active!